Aiming to stop the displacement of hundreds of RV dwellers who have been priced out of the Bay Area’s housing market, two nonprofit legal organizations are challenging Mountain View’s plan to ban oversized vehicles from parking on city streets, calling it cruel and unusual punishment.

The Law Foundation of Silicon Valley and the ACLU of Northern California have sent a letter to Mountain View City Council members demanding that they abandon their plan and reverse a separate city code that bans people who own vehicles that discharge sewage from parking them on city streets.

“Measures like the proposed oversized-vehicle ban that penalize those whose only available shelter is an RV ignore the reality of this hardship and inhumanely punish some of our most vulnerable neighbors,” the nine-page letter states.

The organizations argue that the two measures not only exacerbate the region’s housing crisis and discriminate against the city’s homeless population but also violate the U.S. Constitution.

“When these kinds of parking restrictions are enforced the way they are, and people are forced to constantly move or dodge these kinds of tactics, there is really no stability that they can reach to get into a permanent unit again,” Michael Trujillo, staff attorney of the Law Foundation of Silicon Valley, said in an interview.

Specifically, Trujillo points to a 2018 decision by the Ninth Circuit Court of Appeals in the case of Martin vs. Boise, Idaho, where the panel of judges ruled that “as long as there is no option of sleeping indoors, the government cannot criminalize indigent, homeless people for sleeping outdoors, on public property, on the false premise they had a choice in the matter.”

The judges ruled that doing so would constitute cruel and unusual punishment under the Eighth Amendment.

In a 2017 census of the region’s homeless population, Santa Clara County estimated 8 percent of its 7,400 homeless residents lived in vehicles. San Mateo County estimated that one-third of its 1,250 homeless lived in a vehicle.

The number of vehicle dwellers in Mountain View, in particular, has nearly doubled in the past three years. As of last December, Mountain View city officials identified about 200 RVs serving as homes and another 90 vehicles being used as shelter by city residents.

Addressing complaints and health concerns from residents, the Mountain View city council instructed staff in March to draft an oversized vehicle parking prohibition ordinance — similar to restrictions that have recently been adopted by other Bay Area cities.

The Law Foundation and ACLU argue that the proposed ordinance would “impermissibly punish individuals for merely trying to survive and stay in their home community”, fail to provide equal protection to a particular class of residents, and “restrict freedom of association protected by the First Amendment and the right to travel protected by the U.S. and California constitutions,” according to the nine-page letter.

The organizations further allege that the ban would disproportionately affect residents with disabilities.

More than 42 percent of chronically homeless individuals in Santa Clara County live with a physical disability and over half suffer from a psychiatric or emotional condition — compared to just 4.3 percent and 3.2 percent respectively of the county’s overall population, according to a 2017 county census.

“To be pushing someone out and away from the community where they access that kind of medical care is pretty egregious,” Trujillo said.

At the same time that Mountain View is considering a ban on oversized vehicles, it’s also looking for other ways to accommodate some of those residents.

In March, the council also directed staff to draft a safe parking ordinance aimed at creating secure spots in church and city-owned parking lots for vehicle and RV dwellers to stay at least temporarily.

The move by Mountain View follows in the footsteps of its neighbor East Palo Alto, which earlier this month opened its first safe parking site for RVs. The site — open 7:30 p.m. to 7:30 a.m. — offers up to 20 residents with designated overnight parking space and access to restrooms, portable showers and laundry services.

Mountain View city officials have spent the past several months searching for suitable safe parking sites across the city.

Last week, the council voted to enter a long-term lease with the Santa Clara Valley Transit Authority for a 2-acre property, which gives the city another lot to provide safe parking for up to two years starting this fall.

The lot — located at the corner of Evelyn Avenue and Pioneer Way — served as a transit park-and-ride lot until the Evelyn light rail station closed in 2015. City staff estimated earlier this year that the lot could serve 20 vehicles.

Even with the additional lot, however, an oversized vehicle ban could leave more than 80 percent of the city’s vehicle dwellers without a place to go.

“The idea that the safe parking program is ever going to be able to meet the needs of the population is totally implausible,” Trujillo said.

The council is expected to review draft oversized vehicle and safe parking ordinances at its meeting on June 11. In the letter, the Law Foundation of Silicon Valley and ACLU invite city staff and members of the city council to meet before then.

“We’re certainly hoping to works something out with them, and — with the input of Mountain View vehicle residents — to address this issue in a way that doesn’t involve unconstitutional parking restrictions,” Trujillo said.

Neither the ACLU nor the Law Foundation of Silicon Valley have sued a city for banning RV or vehicle dwelling. However, the ACLU did send a similar letter earlier this year to council members in Crescent City, which resulted in the council tabling the adoption of an ordinance that would have restricted overnight RV parking on city streets.

As of Tuesday afternoon, Trujillo said that the city had not responded to the organizations.

Kimberly Thomas, assistant to the Mountain View city manager, said in a statement Tuesday that the city had received the letter and was reviewing it as part of its ordinance drafting process.

As soaring rent prices have forced thousands of bay area residents to seek shelter in their vehicles, many Bay Area cities have considered and enacted similar bans.

In March, Berkeley became the most recent to prohibit overnight parking of oversized vehicles, including campers and RVs, on its city streets.

Maggie Angst covers government on the Peninsula for The Mercury News. She's a Chicago native and previously covered breaking news for the Milwaukee Journal Sentinel and education for the Island Packet in Hilton Head, S.C.